how i can disable the su command in mandriva and make my user use sudo instead of the su?

I am the opposite and have no sudo installed.... sudo is a separate package that needs root powers to install.

2) but it depends also on what the initial problem is

a) currently user X has root password for doing something and may use it do something you do not want

b) currently user X only needs to run known applications which currently need root powers

c) currently user X has vague needs for occassional root powers and can be trusted


If (a) then sudo is no better solution as once an user is added to sudoers they can run sudo su

if (b) you could change the permissions to (eg) /sbin/appZ to allow group user be set to X

if (c) sudo is fine

3) AFAIK su means set user and su without root means su root but su can not be disabled without having sudo and then you can use sudo to re-enable chmod =x the su command.

You can leave them both installed but restrict who can use them. For su, the file to modify is /etc/suauth. For example, to only allow the user steve to su to root and to deny all others (have a look at man suauth for more info):
For sudo, the file is /etc/sudoers, again the man page for sudoers has config information.

yes gilead and I am just reading LXF mag that you can edit your
/etc/pam.d/su

auth requisite pam_deny.so

will stop all users having su access.

but your distro may currently stop you from logging directly into root so be aware.

hava look at other /etc/pam.d including kdm or gdm